Calculation of foundation Reinforcement Calculation according to EN 1997-1:2008 Foundation geometry - Circular pad for one column

1. Geodomisi Ltd
Dr. Costas Sachpazis
29 Dionysiou Str., Ilion-Athens
Attica 13122 Greece.
Web-Site: www.geodomisi.com
29-Nov-15
Tel.: +30 (210) 523-8127, +30 (210) 571-1263, Fax: +30 (210) 571-1461, Mbl: +30 6936425722
costas@sachpazis.info & csachpazis@tee.gr
Calculation of foundation Reinforcement
Calculation according to EN 1997-1:2008
Foundation geometry - Circular pad for one column
Radius R = 2.00 m
Height of foundation H = 1.20 m
Dimensions of column l1 = 0.50 m
b1 = 0.50 m
Column position ex1 = 0.00 m
exy = 0.00 m
ey = 0.00 m
Soil input
Nr Name Z
[m]
H
[m]
γsoil
[kN/m
3
]
γs
[kN/m
3
]
γd
[kN/m
3
]
φ'
[deg]
C'
[kPa]
Cu
[kPa]
MOi
[kPa]
Mi
[kPa]
1 clayey sands -7.50 7.50 20.00 26.80 20.00 0.40 0.00 74.00 36000.00 36000.00
Foundation formation level zFL = -1.00 m
Foundation cast-in-situ
Bending in direction x - Bottom reinforcement Critical ULS1 As.xreq / As.xprov = 64% Pass

2. Geodomisi Ltd
Dr. Costas Sachpazis
29 Dionysiou Str., Ilion-Athens
Attica 13122 Greece.
Web-Site: www.geodomisi.com
29-Nov-15
Tel.: +30 (210) 523-8127, +30 (210) 571-1263, Fax: +30 (210) 571-1461, Mbl: +30 6936425722
costas@sachpazis.info & csachpazis@tee.gr
Punching shear check Critical ULS1 VEd / VRd.c = 66%
& VEd' / VRd.c max = 38% Pass
Loads
Design load combinations:
Name Limit state VA
[kN]
HxA
[kN]
HyA
[kN]
MxA
[kNm]
MyA
[kNm]
q
[kPa]
ULS1 ULS 1500.00 250.00 0.00 0.00 120.00 5.00
Foundation properties
d1x = 0.060 m
d2x = 0.053 m
Concrete C20/25
fck = 20.00 MPa
γc = 1.50
fcd = 13.33 MPa
Steel B 400 A
fyk = 400.00 MPa
γs = 1.15
fyd = 347.83 MPa
minimum reinforcement ratio ρmin = 0.12 %
maximum reinforcement ratio ρmax = 4.00 %

3. Geodomisi Ltd
Dr. Costas Sachpazis
29 Dionysiou Str., Ilion-Athens
Attica 13122 Greece.
Web-Site: www.geodomisi.com
29-Nov-15
Tel.: +30 (210) 523-8127, +30 (210) 571-1263, Fax: +30 (210) 571-1461, Mbl: +30 6936425722
costas@sachpazis.info & csachpazis@tee.gr
Reinforcement ratio ρ = 0.00 %
Bending in direction x - Bottom reinforcement
ULS1 As.xreq / As.xprov = 64% Pass
Design bending moment in direction x My = 951.12 kNm
Theoretical area of reinforcement in
direction x
As.xreq = 30.37 cm
2
/m
Provided area of reinforcement in
direction x
As.xprov = 47.12 cm
2
/m
Punching shear check
ULS1 VEd VRd.c = 66% & VEd' VRd.c max = 38% Pass
β = 1.68
u1 = min(4 * π * d + 2 * l1 + 2 * b1, 2 * (B + L)) = 10.30 m
u0 = 2 * l1 + 2 * b1 = 3.14 m
Net applied force VEd = β * VEd,red / (u1 * d) = 428.54 kN
VEd' = β * VEd,red / (u0 * d) = 1405.62 kN
CRd.c = 0.18 / γc = 0.12
k = min(1 + sqrt(200 / d), 2) = 1.59
ρL = min(sqrt(ρx * ρy), 2) = 2.00 %
Vmin = 0.035 * k
3 /2
* fck
1 /2
= 249.24 kN
Punching shear capacity at control
perimeter at distance 2*d from column
edge
VRd.c = min(C Rd.c * k * (100 * ρL * f ck)
1/3
, V min) * 2 * d / a = 653.49 kN
ν = 0.6 * (1 - f ck / 250 MPa) = 0.55
Maximum punching shear capacity
column perimeter
VRd.c max = 0.5 * ν * f cd = 3680.00 kN

4. Geodomisi Ltd
Dr. Costas Sachpazis
29 Dionysiou Str., Ilion-Athens
Attica 13122 Greece.
Web-Site: www.geodomisi.com
29-Nov-15
Tel.: +30 (210) 523-8127, +30 (210) 571-1263, Fax: +30 (210) 571-1461, Mbl: +30 6936425722
costas@sachpazis.info & csachpazis@tee.gr